Method and control system for operating a rolling mill

Abstract

The present invention relates to a method and control system for operating a rolling mill for rolling a material, preferably a metal. This method and control system is particularly used to set the roll gap of a rolling mill to ensure that the material passes straight through the mill. For this purpose, a pre-calculated reference meander value is added to the control signal to the actuator 120 for setting the roll gap. To eliminate the need for the conventional additional manual correction setting of the reference meander value for or during the rolling process, the method and control system of the present invention propose that a continuous meander value transition during the rolling of the material i is calculated, and this meander value transition x is evaluated to calculate the actual meander value for the leading and / or trailing end of the material, taking into account a pre-generated reference meander value.

Description

Technical Field

[0001] The present invention relates preferably to a method and a control system for operating a rolling mill (roll stand) in order to roll a metal material to be rolled, such as a metal steel plate or a flat product or a sheet material, and reduce its thickness. This method and this control system are particularly used for setting the roll gap of the rolling mill in order to ensure that the material to be rolled passes straight through the rolling mill. Furthermore, the present invention relates to a rolling mill having such a control system. The present invention can be used in a rolling mill for hot rolling or cold rolling a material to be rolled. The rolling mill may be a single stand or a roll stand in a rolling line, such as a tandem mill. The rolling mill may be, for example, a front stand in a rolling line, a Steckel mill or a reversing mill. Finally, the present invention also relates to various usage methods for the roll stand and the basic snake (Schwenk) value calculated according to the present invention.

Background Art

[0002] Methods and control systems for setting the roll gap between the work rolls of a rolling mill are basically known in the prior art. This method and this control system are used to make the material to be rolled travel straight through the rolling mill, that is, to pass through stably. This method and this control system can also be used to set a wedge region in the material to be rolled, that is, a wedge-shaped cross section. When deviating from the straight travel, the tip of the material to be rolled may not reach the subsequent processing device. The trailing end of the material to be rolled may flow laterally. In this case, for example, it contacts a guide provided in front of the rolling mill and may be mechanically damaged in some cases.

[0003] To ensure sufficiently stable straight-line movement, it is common practice to pre-set the work rolls, or roll gap, of the rolling mill before rolling the material to be rolled, using a so-called basic meandering setting. The meandering setting involves setting the positional difference between the drive side and the work side in the rolling mill's adjustment device. In some cases, this positional difference arises from an inconsistent roll gap width between the drive side and the operating side. Such a setting is particularly necessary after roll replacement or work roll calibration, because, in these cases, it is generally necessary to first find an appropriate new meandering state. Essentially, the basic meandering setting is maintained throughout the subsequent rolling process and, conventionally, is generally changed only when necessary, either by the operator or the rolling mill's automatic control.

[0004] In many cases, different basic meandering settings are implemented depending on the boundary conditions resulting from the rough rolling process or the boundary conditions of the rolling material being fed to the leading and trailing ends of the rolling material.

[0005] Various methods for simulating the automatic meandering of work rolls in a rolling mill are known in the patent literature.

[0006] European Patent Application Publication No. 0875303 discloses a meandering control method for accurately calculating the difference in rolling force.

[0007] German Patent Application Publication No. 3837101 discloses a control principle for measuring the position of a steel plate.

[0008] Japanese Patent Publication No. 2004-237313 discloses a control method that adjusts the meandering state of a steel plate, particularly its tail end, after it has passed through a preceding rolling mill, based on the position measurement of the steel plate.

[0009] European Patent Application Publication No. 3202502 discloses predictive control based on position measurement of the leading edge of a steel sheet until it reaches a subsequent rolling mill.

[0010] Known methods for controlling meandering or turning conditions from the measurement of rolling force difference or the position of steel plates greatly improve the situation. These methods respond to the current measured variables by changing the gap setting. However, even with control based on precisely calculated rolling force difference, it is not possible to keep the system and control within the normal operating range.

[0011] The same applies to meandering control by measuring the position of the steel sheet. Only when the first measurement is provided, that is, only after passing through half of the middle section of the rolling mill, can this meandering control intervene with respect to the leading edge of the steel sheet. Until then, the steel sheet is rolled by the operator without control by the reference meandering value, and in some cases, under suboptimal conditions.

[0012] The same applies to the tail end of the steel plate. In this case, the meandering control can be intervened immediately after a change in the position of the steel plate is detected by measurement. A change in the position of the steel plate occurs, for example, when the reference meandering value of the rolling mill is not optimal. [Prior art documents] [Patent Documents]

[0013] [Patent Document 1] European Patent Application Publication No. 0875303 [Patent Document 2] German Patent Application Publication No. 3837101 [Patent Document 3] Japanese Patent Publication No. 2004-237313 [Patent Document 4] European Patent Application Publication No. 3202502 [Overview of the project] [Problems that the invention aims to solve]

[0014] The object of the present invention is to improve known methods and control systems for operating a rolling mill, particularly for setting the roll gap of a rolling mill, a corresponding known roll stand, and a known method for using a reference meander value, such that, as a result of determining at least one reference meander value for adjusting the roll gap, no further manual setting or correction of the reference meander value is required for the rolling process. [Means for solving the problem]

[0015] This problem is solved with respect to the method described in claim 1. This method is characterized in that a continuous meandering value transition is calculated for the rolled material i, and the actual meandering values ​​for the leading edge and / or trailing edge of the rolled material are calculated by evaluating the continuous meandering value transition while considering the basic meandering values ​​for the leading edge and / or trailing edge of the rolled material i.

[0016] The term "rolled material" specifically refers to metal sheets or metal plate products. The term "reference meander value" represents the meander set value that should be or has been performed in the rolling mill, as defined in the description of the prior art above. The term "actual meander value" refers to the evaluated meander value transition with respect to the leading and / or trailing ends of the rolled material i.

[0017] The method of the present invention as described in the claims defines automatic control. In this automatic control, reference meander values ​​for the leading and / or trailing ends of the rolled material are determined as control variables for actuators for setting the roll gap in the rolling mill. Within the range of this control, at least one target meander value is compared with at least one actual meander value to calculate a meander error, i.e., a control deviation, as necessary. The control device then calculates the reference meander value necessary to set the roll gap from this meander error. A feature of the method of the present invention lies in calculating the above-mentioned actual meander value. According to the present invention, this actual meander value is calculated by the method steps characterized above. This particular method of the present invention for calculating the actual meander value benefits the fully automatic and accurate calculation of the reference meander value. As a result, manual correction intervention by the rolling mill operator is no longer required.

[0018] The method of the present invention enables the automatic determination of a reference meander value for the leading edge of a rolled material. The rolled material is set to this reference meander value before the start of rolling. Alternatively, or further, the method of the present invention enables the determination of a reference meander value for the trailing edge of a rolled material. In this case, this reference meander value is set in the rolling mill at least before the rolled material leaves the current rolling mill. Two different reference meander values ​​may be determined for the leading edge and trailing edge of a rolled material. Control of the rolling mill's roll gap to reduce the thickness of the leading edge, central region, and trailing edge of the rolled material is performed independently of the method of the present invention for determining the reference meander values. The determination and setting of at least one reference meander value is used solely to ensure that the rolled material passes straight through the rolling mill. The setting of the reference meander value is subordinate to or takes precedence over the control of the rolling mill's roll gap to reduce the thickness.

[0019] Therefore, the term "control signal for actuator" in this specification refers only to the component of the total control signal for actuator that ensures the straight movement of the rolled material by a reference meandering value. Here, the term "control signal" does not correspond to reducing the thickness of the rolled material as needed.

[0020] Each time the operating state of the rolling mill changes significantly, the reference snaking value may be reset to a preset value. This is beneficial, for example, when replacing the rolling mill or switching to the coil box operation. According to the first embodiment of the method of the present invention, the continuous snaking value transitions for the rolled material i, which are necessary for calculating the actual snaking value according to the present invention, can be calculated in three different ways. According to the calculation according to at least one of these three options, the output signal of the snaking control device is used. In this case, this snaking control device can be configured in various ways even in the case of the second embodiment of the present invention. For example, the snaking control device can be based on the rolling force difference and / or the position measurement of the steel plate. In any case, the snaking control device evaluates the process variables supplied to this snaking control device in order to calculate its output signal. The third embodiment relates to a method for evaluating the continuous snaking value transitions in order to calculate the actual snaking value.

[0021] The rolling mill may be, for example, a reversing rolling mill. In this case, the method of the present invention is not only executed independently for the forward rolling direction but also for the reverse direction, that is, the reverse rolling direction, and it is desirable to generate not only separate reference snaking values for the leading end and / or the trailing end of the rolled material i but also separate reference snaking values for each of the forward pass and the reverse pass of the rolled material i.

[0022] To ensure a smooth transition without impact, the transition between two different reference snaking value settings should be executed continuously, particularly in a ramp-like manner. The reference snaking value for the leading end of the rolled material should be maintained at least until this rolled material reaches, for example, a subsequent rolling mill in the rolling line. The reference snaking value for the trailing end of the rolled material should be maintained until the rolled material exits the current rolling mill.

[0023] Furthermore, the above problems of the present invention relate to the control system according to claim 8, the rolling stand according to claim 9, and the method of use according to claim 10. The advantages of these solutions are consistent with the advantages described for the above method.

[0024] Other advantageous configurations of the method, control system, and rolling stand of the present invention are described in the dependent claims.

[0025] The method of the present invention is configured for individual use with a specific rolling mill. When a plurality of rolling mills are arranged in a rolling line, the method of the present invention and the control system of the present invention are used independently of each other for each of these individual rolling mills. By the method of the present invention, first, a reference snaking value is determined for rolling the current material to be rolled during rolling. At this time, according to the present invention, the reference snaking value thus calculated can be used as follows. For example, by using these reference values, a rolling mill arranged subsequently in the rolling line can be preset before the same material to be rolled passes through this rolling mill. Instead, the reference value thus calculated is maintained as a preset value for the current rolling mill for rolling subsequent materials to be rolled that are equivalent to or at least similar to the current material to be rolled. Further, instead of this, when the rolling mill is a reversing rolling mill, for newly rolling the current material to be rolled in the reverse direction, that is, in the reverse rolling direction, the reference snaking value calculated according to the present invention can be maintained as a preset value for the actual rolling mill. The expression "presetting of the rolling mill according to the reference snaking value" means that a control signal for an actuator for setting the roll gap of the rolling mill is generated based on the reference snaking value, and this actuator is controlled by this control signal.

Brief Description of the Drawings

[0026] [Figure 1] The control system of the present invention is shown in a simplified manner. [Figure 2] The control system of the present invention is shown in more detail. [Figure 3] An embodiment of the snaking control device is shown. [Figure 4] The determination of the reference snaking value of the tip of the material to be rolled according to the present invention is shown. [Figure 5] The determination of the reference snaking value of the tail end of the material to be rolled according to the present invention is shown. [Figure 6] This method demonstrates that, when the current rolled material and the subsequent rolled material are rolled in the same current rolling mill, new reference meander values ​​for the leading and trailing ends of the subsequent rolled material i+1 are determined based on the meander value transition x for the currently rolled material i. [Figure 7] This method demonstrates how, when the currently rolled material is to be rolled in at least one subsequent rolling mill after it leaves the current rolling mill, new reference meander values ​​are determined for the leading and trailing ends of the subsequent rolled material i+1, based on the meander value transition for the currently rolled material i. [Modes for carrying out the invention]

[0027] The present invention will be described in detail below with reference to the above-mentioned figures illustrating embodiments. In all figures, the same technical elements are indicated by the same reference numerals. All values, errors, and signals, i.e., signal transitions, are considered to be time-dependent even if their reference numerals are not explicitly indicated with (t). Constant values ​​correspond to signal transitions that are constant in time.

[0028] Figure 1 shows a control system 100 of the present invention for operating a rolling mill F_j having two work rolls for forming a roll gap and rolling a material i, particularly a metal steel sheet. The control system 100 consists of an actuator 120 for adjusting the roll gap and a control device 110 for generating at least one reference meandering value delta sk_i, delta se_i for the leading and / or trailing ends of the material i to be rolled, as a reference for the control signal for the actuator 120. The control device 110 calculates basic meandering values ​​delta sk_i, delta se_i according to the received meandering errors e_delta sk_i, e_delta se_i, such that the meandering error corresponding to the control deviation becomes as close to zero as possible. The meandering error is similarly calculated by a comparator 160, which is a component of the control system 100, as the difference between predetermined target meandering values ​​delta sk_w, delta se_w for the leading and / or trailing ends of the rolled material and the actual meandering values ​​delta sk'_i, delta se'_i for the leading and / or trailing ends of the rolled material.

[0029] Furthermore, the control system 100 includes an evaluation device 140 for calculating the actual meandering value. The evaluation device 140 calculates the actual meandering values ​​delta sk'_i and delta se'_i for the leading and / or trailing ends of the rolled material i, respectively, by evaluating the received continuous meandering value transition x, while considering the basic meandering values ​​delta sk_i and delta se_i for the leading and / or trailing ends of the rolled material i. Figure 2 shows different variations for calculating or selecting the continuous meandering transition. Specifically, multiple different representative signals can be recognized. One of the representative signals can be selected as the continuous meandering value transition x. Examples of representative signals or continuous meandering value transitions include: -Time progression of the control signal delta s_i(t) for actuator 120, or - The continuously measured output signal delta sr_i(t) of actuator 120, or - The continuous transition of the shape of the roll gap delta sg_i(t) in the case of a rolling mill F_j for a rolled material i, This could be selected.

[0030] To evaluate the selected sequence of meandering value transitions x, the evaluation device 140 performs, for example, the following partial steps. - An average value of a continuous meandering value transition (x) is formed over a predetermined period of time or over a predetermined length section of the rolled material i. In this case, this period or length section corresponds, for example, to the leading edge, central region, or tail end of the rolled material i. - The difference between the reference meandering values ​​delta sk_i, delta se_i and the average value is formed for the leading edge and / or trailing edge and / or central region of the rolled material i. -This difference is weighted by a predetermined coefficient. In this case, the weighted difference corresponds to the actual meander values ​​delta sk'_i and delta se'_i that should be generated.

[0031] When performing the initial sub-step using the first bulleted list, the following variations can be distinguished:

[0032] If a subsequent rolling mill F_j+1 is positioned behind rolling mill F_j in the rolling direction, the time required from when the material to be rolled i becomes engaged in the target rolling mill F_j until it becomes engaged in the subsequent rolling mill F_j+1 may be selected as the period for forming the average value.

[0033] Alternatively, or in addition to this, if a preceding rolling mill F_j-1 is positioned in front of the rolling mill F_j in the rolling direction, the time required from when the rolled material i leaves the preceding rolling mill F_j-1 until it leaves the target rolling mill F_j may be selected as the period for forming the average value.

[0034] Furthermore, Figure 2 shows that the control signal delta s_i(t) for the actuator 120 can be formed by the adder 170 as the sum of reference meandering values ​​delta sk_i, delta se_i for the leading and / or trailing ends of the rolled material and the time-continuous total output signal delta sc_i(t) of the meandering control device 150.

[0035] Figure 3 shows an embodiment of the meandering control device 150. Basically, this embodiment is known in the prior art. The meandering control device controller 150 consists of one or more partial meandering controllers 150-1…N. These output signals can be selectively added to a temporally continuous total output signal delta sc_i(t). A partial meandering controller is, for example, - A meandering controller based on the differential force delta F(t), which is calculated as the difference between the change in the force applied by the operating side and the change in the force applied by the moving side. - A meandering controller based on the center position delta x(t) of the rolled material, and / or - A meandering controller based on other process variables delta nn(t), It is possible.

[0036] As an option, the meandering control device 150 may also take into account operational intervention by the rolling mill operator when determining the total output signal delta sc_i(t). Figures 4 to 7 that follow illustrate the generation of a reference meandering value according to the invention and the beneficial effects of using the reference meandering value for different usage conditions.

[0037] Figure 4 is divided into an upper half and a lower half. The upper half shows the rolling of the material to be rolled without setting a reference meander value according to the present invention. In contrast, the lower half shows the beneficial effect of counteracting lateral flow of the material to be rolled when using the reference meander value according to the present invention. Each half of the two halves shows two rolling mills F_j+1 (represented by two wider rolls aligned vertically) arranged one behind the other in the rolling direction of the rolling line. The rolling direction is indicated by a black arrow pointing to the right. For example, support rolls or roller conveyors (represented by narrower rolls) are placed between the rolling mills. This arrangement of rolling mills is shown in three rows side by side horizontally. In this case, each depiction shows different time points t1, t2, and t3 when the material to be rolled i is actually being rolled. In the first depiction, the material to be rolled i is moving straight towards the first rolling mill F_j. In the second depiction t2, the rolled material i is supported by a support roll or roller conveyor before passing through the first rolling mill F_j and reaching the subsequent rolling mill. In this case, the rolled material i is laterally shifted upward, i.e., to the left with respect to the rolling direction. The third depiction t3 shows the subsequent movement of the laterally shifted rolled material i. It can be seen that, due to this lateral flow, the rolled material is no longer centered but laterally shifted to the subsequent rolling mill F_j+1. This is undesirable.

[0038] Below the three depictions of the rolling mills above, the transition of the control signal to the actuator of the roll gap of the first rolling mill F_j is shown, as the control signal is involved in correcting the straightness of the rolled material. If the rolled material i has not yet passed through rolling mills F_j and F_j+1, there is no need to significantly change the control signal delta s_i(t) to these rolling mills, nor is it necessary to assign a reference meander value. However, immediately after the lateral flow at the leading edge of the rolled material i is recognized in the second depiction t2 after passing through the first rolling mill F_j, counter-control is attempted by the corresponding change in the control signal delta s_i(t), shown by the transition of the dotted line. The large change in the illustrated control signal is mainly caused by the meander control device 150, which recognizes the lateral flow at the leading edge of the rolled material as shown in the second depiction t2. As a result, the meander control device 150 changes its entire output signal. This causes the control signal delta s_i(t) to the actuator 120 to be automatically and appropriately modified. Consequently, the lateral flow of the rolled material i is slightly reduced, as shown in the third drawing t3. This reduction in lateral flow is also recognized, and the amplitude of the control signal is reduced accordingly. Despite the very large change in the illustrated control signal, feeding the leading edge of the rolled material into the center of the subsequent rolling mill F_j+1 as a result of adequately compensating for the lateral flow of the leading edge is often not achievable. In other words, stable straight-line movement of the rolled material i is still not guaranteed.

[0039] Here, the present invention, and in particular the method of the present invention, is used. As illustrated in the lower half of Figure 4, here, for example, the time progression of the control signal delta s_i(t) to actuator 120 is used for a continuous meandering value progression x, and is used as a so-called control variable to control the setting of the roll gap of the rolling mill in order to ensure that the rolled material passes straight through the rolling mill. For this reason, the method of the present invention first proposes that the control signal, i.e., the continuous meandering value progression x, is evaluated considering reference meandering values ​​delta sk_i, delta se_i for the leading edge of the rolled material i. This evaluation is performed in the evaluation device 140 in the manner described in detail in Figure 1 above. The result of this evaluation is the actual meandering value delta sk'_i for the leading edge of the rolled material. In the method or control of the present invention, if necessary, a control deviation is calculated as a meandering error e_delta sk_i for the leading edge of the rolled material. This actual meandering value is compared by the comparator 160 with a predetermined target meandering value (standard value is zero) for the leading edge of the rolled material. In the subsequent rolling mill F_j+1, or in the case of a reverse rolling mill, in the same rolling mill F_j, this meandering error is input to the control device 110 as an input signal for calculating a reference meandering value delta sk_i for the subsequent rolling process.

[0040] The lower half of Figure 4 shows the beneficial effect when a reference meandering value already calculated for the rolled material i according to the present invention is used to initialize the rolling mill for rolling the subsequent rolled material i+1. The reference meandering value delta sk_i+1 calculated according to the present invention is already added to the control signals for the rolling mills F_j and F_j+1 before rolling of the rolled material i+1 begins. Here, this reference meandering value is, for example, constant and preferably held while the rolled material i+1 passes through both rolling mills. The beneficial effect of this initialized setting is evident at the second time point t2' shown in the second depiction t2'. In this case, it can be seen that the lateral displacement of the leading edge of the rolled material i+1 is significantly smaller than the lateral displacement of the rolled material i at time point t2 in the figure above. Nevertheless, even this slight lateral deviation is recognized, for example, by the meandering control device 150, and the control signal delta s_i+1(t) is further corrected, as shown by the dotted line transition in the lower half of Figure 4. Preferably, since the reference meandering value calculated according to the present invention is already pre-added to the control signal delta s_i+1 from t1' onward, only relatively small changes or corrections to the control signal are required from the second time point t2' onward, as shown by the dotted line in Figure 4. This is far more beneficial to process stability than the very large changes in signal transitions that are conventionally required in the upper time chart of Figure 4. The control signal acting according to the present invention at this time consists of the above-mentioned reference meandering value component and a smaller correction component following the dotted line transition, and as shown in the third time point t3' in the lower half of Figure 4, the lateral displacement of the leading edge of the rolled material i+1 between the rolling mill F_j and F_j+1 is significantly reduced overall.

[0041] The time progression of the control signals in the upper and lower halves of Figure 4 are applied only to the rolling mill F_j, but they are also applied to different rolled materials i and i+1. For the subsequent rolling mill F_j+1, the method of the present invention is separately and anewly executed, and a reference meandering value is newly calculated for the rolled material i+1 to be rolled by the rolling mill F_j+1 when the rolled material i is being rolled by the rolling mill F_j+1. Accordingly, a new control signal is also calculated for the actuator of the subsequent rolling mill F_j+1, and the actuator 120 or roll gap is newly and separately adjusted to roll the rolled material i+1.

[0042] Figure 5 is similarly applied to the explanation in Figure 4, but differs significantly in that it illustrates the method of the present invention for calculating the reference meandering value with respect to the tail end of the rolled material rather than the leading end. Here, the lateral displacement of the tail end of the rolled material i is detected not immediately before the rolling mill F_j at time t2, but only when the rolled material i has already passed the rolling mill F_j and a portion of it has already been rolled in the subsequent rolling mill F_j+1. Here, this detection is also performed, for example, by the meandering control device 150, which causes the necessary significant change in the control signal delta s_i(t)F_j+1 for the subsequent rolling mill F_j+1 shown in the upper half of Figure 5. After the rolled material i has passed the subsequent rolling mill F_j+1, the control signal abruptly returns to zero after the large change in this control signal.

[0043] In this embodiment as well, the transition of the control signal delta s_i(t) is evaluated by the evaluation device 140 to calculate the actual meandering value delta se'_i. The actual meandering value delta se'_i is compared by the comparator 160 with a predetermined target meandering value for the tail end of the rolled material i. As a result, the meandering error e_delta se_i that may occur is converted by the control device 110 into a reference meandering value delta se_i+1 for the tail end of the rolled material i+1. This reference meandering value, thus calculated, is also pre-added to the control signal for the actuator 120 of the subsequent rolling mill F_j+1 immediately after the rolled material i+1 has passed through the first rolling mill F_j. Here again, this reference meandering value is kept constant over time, preferably at least until the rolled material i+1 has passed through the rolling mill F_j+1 at time t3'. If, as the rolled material i+1 passes through the rolling mills F_j and F_j+1, a smaller lateral deviation at the tail end of the rolled material i+1 is detected, the control signal may include a temporally constant reference meander value, as indicated by the progression of the dotted line in the control signal, so that it can be recognized in the temporal progression of the lower control signal.

[0044] Figure 6 shows the change in the time course of the control signal, which is greatly affected by the change in the reference meander value as the rolled material i passes through the rolling mill F_j. The change in the time course of the control signal is due to the fact that the reference meander values ​​are different for the leading and trailing ends of the rolled material. The signal components of the control signal, shown by the solid black line, represent the change in the time course of the reference meander value delta sk_i for the leading end of the rolled material and the reference meander value delta se_i for the trailing end of the rolled material. The actual change in the control signal delta s_i(t) for the actuator 120 of the rolling mill F_j is shown by the dotted line, and it may temporarily deviate from the superimposed reference meander value. As described above, this deviation is due to the lateral flow motion that may be temporarily detected when the rolled material i passes through the rolling mill F_j. First, it can be recognized that a reference meander value for the control signal for the leading edge of the rolled material i is added before rolling begins in the rolling mill F_j, and then cut off again before the rolled material i has completely passed through the rolling mill F_j. Before the tail end of the rolled material i is fed into the rolling mill F_j, the reference meander value delta se_i, which has already been calculated in advance for the tail end of the rolled material i, is added to the control signal. As a result, after the reference meander value component delta sk_i for the leading edge of the rolling mill is cut off at time t4, this control signal is greater than zero rather than reduced to zero, as shown in the upper part of Figure 6 (see signal height for control signal delta se_i).

[0045] According to the method of the invention, this signal transition is used to determine new reference meander values ​​for the leading and trailing ends of the subsequent rolled material i+1 to be rolled. This is performed separately for the leading and trailing ends of the rolled material by the evaluation device 140, comparator 160, and control device 110, respectively. As a result, by using the method of the invention, new reference meander values ​​delta sk_i+1 and delta se_i+1 are generated for the subsequent rolled material i+1 to be rolled. These new reference meander values ​​also form a reference for the control signal delta s_i+1(t) for controlling the actuator 120 for the rolling mill F_j when the rolling mill F_j rolls the subsequent rolled material i+1 (see lower half of Figure 6). Similar to the explanation of the signal transition in the upper diagram of Figure 6, the control signal delta s_i+1(t) is basically generated by superimposing the meandering value for the leading end of the rolled material i+1 with the meandering value for its trailing end, with a time lag.

[0046] By using a ramp, a smooth transition between a reference meander value for the leading end of the rolled material and a reference meander value for the trailing end can be obtained. This is beneficial for process stability. As described above, in order to determine the reference meander value for the leading end of the rolled material and a reference meander value for the trailing end, the transition of the corresponding control signal delta s_i(t) is evaluated. This time signal can be appropriately limited to the first 5m for the leading end of the rolled material and appropriately limited to the last 5m for the trailing end of the rolled material.

[0047] The explanation for Figure 6 also applies to Figure 7. Unlike Figure 6, Figure 7 shows the progression of the control signal delta s_i(t) for the current rolling mill F_j when the material to be rolled i has already passed through the previous rolling mill F_j-1 before passing through rolling mill F_j+1. [Explanation of Symbols]

[0048] 100 control systems 110 Reference meandering value of the control device 120 Actuators 140 Evaluation device 150 Snake Track Control Device 160 comparators 170 Adder delta sk_w: Target meandering value relative to the leading edge of the steel plate (standard value is zero) delta se_w: Target meandering value relative to the tail end of the steel plate (standard value is zero) e_delta sk_i: Meanchout error of steel plate i relative to the leading edge of the steel plate e_delta se_i: Meanchout error of steel plate i relative to the tail end of the steel plate. delta sk_i: Reference meandering value of steel plate i relative to the leading edge of the steel plate. delta se_i: Reference meandering value of steel plate i relative to the rear of the steel plate. Process variables: A multidimensional signal containing all existing process variables. delta sc_i(t): A continuous combined output signal as the sum of all meandering control devices and operator interventions on steel plate i. delta s_i(t): Time progression of the control signal for the actuator, which serves as a representative signal representing the progression of continuous meandering values ​​for steel plate i. delta sr_i(t): The continuously measured output signal of the actuator, which serves as a representative signal representing the continuous meandering value transition for steel plate i. Disturbances: Multidimensional signals of measurable and unmeasurable disturbances in the rolling process. delta sg_i(t): Time evolution of the roll gap shape relative to steel plate i, which is a representative signal representing the continuous meandering value progression relative to steel plate i. delta sk'_i: The change in the evaluated meandering value relative to the leading edge of steel plate i (= the actual meandering value relative to the leading edge of the rolled material i) delta se'_i: The change in the evaluated meandering value of steel plate i relative to the tail end (= the actual meandering value of the rolled material i relative to the tail end) delta F(t): Change in continuous rolling force difference delta x(t): Change in the position of a continuous steel plate delta nn(t): The continuous measurement progression of other process variables (e.g., inlet guide force, work roll axial force, etc.) delta s_F(t): Continuous meandering value of the rolling force difference control device. delta s_x(t): The continuous meandering value of the steel plate position control device. delta s_nn(t): The continuous meandering value of other control devices. delta s_Bed(t): The change in continuous meander values ​​due to operator intervention. delta sk_i-1: Reference meandering value for the leading edge of steel plate i-1 delta se_i-1: Reference meandering value of steel plate i-1 relative to the tail end of the steel plate. F_j-1 Preceding Rolling Mill F_j - Rolling mill F_j+1 Subsequent rolling mill (= successor rolling mill) i-1 The previously rolled material i. Rolled material being actually rolled i+1 The subsequent rolled material to be rolled Changes in the continuous meandering value for steel plate i x t1, t2, t3, t4 Different points in time during the rolling process of the rolled material. t1', t2', t3', t4' Different points in time during the rolling process of the rolled material.

Claims

1. A method for operating a rolling mill (F_j) to roll a rolled material i, particularly a metal steel sheet, A control system (100) having an actuator (120) for adjusting the roll gap of the rolling mill and a control device (110) for generating a reference meander value for controlling the actuator is attached to the rolling mill (F_j). below, - A step of setting a target meandering value (delta sk_w) for the leading end of the rolled material i and / or a target meandering value (delta se_w) for the trailing end of the rolled material i, - In order to calculate the meandering error (e_delta sk_i, e_delta se_i) for the leading edge and / or trailing edge of the rolled material, the steps include comparing the target meandering values ​​(delta sk_w, delta se_w) for the leading edge and / or trailing edge of the rolled material i with the actual meandering values ​​(delta sk'_i, delta se'_i) for the leading edge and / or trailing edge of the rolled material, - A step in which the control device (110) generates basic meander values ​​(delta sk_i, delta se_i) for the leading and / or trailing ends of the rolled material i in accordance with this reference meander value, so that the meander error is as close to zero as possible, In the method having, The continuous meandering value change (x) is calculated during the rolling of the rolled material i. The method is characterized in that the actual meandering values ​​(delta sk'_i, delta se'_i) for the leading and / or trailing ends of the rolled material are calculated by evaluating the continuous meandering value transition (x) while considering the basic meandering values ​​(delta sk_i, delta se_i) for the leading and / or trailing ends of the rolled material i.

2. It is one of the following signals: - The time progression of the control signal (delta s_i(t)) for the actuator (120), which is formed by the adder (170) as the sum of the reference meandering values ​​(delta sk_i, delta se_i) for the leading and / or trailing ends of the rolled material and the time-continuous total output signals (delta sc_i(t)) of the meandering control device (150), or - Continuously measured output signals (delta sr_i(t)) of the actuator (120), or - The continuous transition of the roll gap shape (delta sg_i(t)) in the case of a rolling mill (F_j) for the material i to be rolled is, The method according to claim 1, characterized in that it is selected and calculated as a representative signal for a continuous meandering value transition (x).

3. At least one meander control device (150) - A meandering control device based on the change in differential force calculated as the difference between the change in the force applied on the operating side and the change in the force applied on the operating side of the rolling mill. - A meandering controller based on the center position of the rolled material as it passes through, and / or - A meandering controller based on other process variables, The method according to the present invention, characterized in that...

4. The evaluation of the continuous meandering value change (x) is as follows: - A partial step that forms the average value of a continuous meandering value transition (x) over a predetermined period or over a predetermined length section of the rolled material i, wherein the period or length section corresponds, for example, to the leading edge, central region or tail end of the rolled material i, - A partial step that forms the difference between the reference meandering value (delta sk_i, delta se_i) and the average value for the leading edge and / or trailing edge and / or central region of the rolled material i, - A sub-step in which this difference is weighted by a predetermined coefficient to generate the actual meandering values ​​(delta sk'_i, delta se'_i), The method according to any one of claims 1 to 3, characterized by including the following:

5. In order to calculate the actual meandering value relative to the leading edge of the rolled material, if the subsequent rolling mill (F_j+1) is positioned behind the rolling mill (F_j) in the rolling direction, the time required from when the rolled material i is bitten into the target rolling mill (F_j) until it is bitten into the subsequent rolling mill (F_j+1) is selected as the period for forming the average value, and / or The method according to 4, characterized in that, in order to calculate the actual meandering value relative to the tail end of the rolled material, when the preceding rolling mill (F_j-1) is positioned in front of the rolling mill (F_j) in the rolling direction, the time required from when the rolled material i leaves the preceding rolling mill (F_j-1) until it leaves the target rolling mill (F_j) is selected as the period for forming the average value.

6. The rolling mill (F_j) is a reverse rolling mill, The method according to any one of claims 1 to 5, characterized in that the method is performed independently of forward rolling and reverse rolling, and generates not only separate reference meander values ​​(delta sk_i, delta se_i) for the leading and / or trailing ends of the rolled material i, but also separate reference meander values ​​(delta sk_i, delta se_i) for the forward and reverse paths of the rolled material i, respectively.

7. The method according to any one of claims 1 to 6, characterized in that, in a rolling mill, the setting of the reference meander value from a preceding value to a new value is changed continuously, particularly in a ramp-like manner, while the rolling mill is in operation.

8. An actuator (120) for setting the roll gap in the rolling mill (F_j) in order to roll the material i to be rolled, A comparator (160) for calculating the meandering error (e_delta sk_i, e_delta se_i) as the difference between the target meandering value and the actual meandering value for the leading and / or trailing ends of the rolled material i, A control device (110) for generating reference meandering values ​​for the leading and / or trailing ends of the rolled material i, according to the meandering error, as a reference for the control signal for the actuator (120), A control system for operating a rolling mill (F_j) with two work rolls that form a roll gap in order to roll a material i, particularly a metal steel sheet, having the following: The control system (100) includes an evaluation device (140) for calculating the actual meandering values ​​relative to the leading edge and / or trailing edge of the rolled material. A control system having this evaluation device is configured to perform the method described in any one of claims 1 to 7.

9. In a roll stand having two work rolls that form a roll gap for rolling a rolled material i, particularly a metal steel sheet, The roll stand is characterized by the attached control system (100) described in claim 8.

10. A method by which reference meandering values ​​(delta sk_i, delta se_i) generated by a rolling mill (F_j) are used with respect to the leading and / or trailing ends of a rolled material i by the method of any one of claims 1 to 7, below, - Usage conditions for controlling the actuator of a subsequent rolling mill (F_j+1) located downstream of rolling mill (F_j) in the rolling line, in order to roll the same material i after it has passed through rolling mill (F_j), or - Usage conditions for controlling the action (120) of the rolling mill (F_j) in order to roll the rolled material i or the subsequent rolled material i+1 in the same rolling direction as the rolled material i, or --When the rolling mill is a reverse rolling mill--In order to roll the material i in the reverse rolling direction, the operating conditions for controlling the actuator of the rolling mill (F_j+1) The method used to generate a control signal (delta s_i(t)) for [something].

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